FIGS. 4a and 4b illustrate a general manufacturing method of a so-called optical connector in which optical fibers are attached to a ferrule for optical connector. As shown in FIG. 4a optical fibers 12 of an optical fiber core line 10, the covering 11 of which is removed in advance, are inserted into an optical fiber insertion ports 22 attached to a ferrule for optical connector 21.
Next, the optical fibers 12 are fixed at the optical connector ferrule 21 by pouring an adhesive agent 7 through an adhesive agent supplying port 23 secured at the optical connector ferrule 21 in a state where the leading edges of optical fibers inserted as shown at (b) in the same drawing are caused to come out from the optical fiber inserting port 22 of the optical connector ferrule 21.
Thereafter, an optical connector 24 can be obtained by polishing (mirror-finishing) the end face which is in a state that the optical fibers 12 go through the end face.
In FIGS. 4a and 4b, number 25 is a fitting pin hole for axial alignment.
There are the following problems when polishing (mirror-finishing) the end face of the optical connector, from which the following shortcomings come out.
Usually, a ferrule 12 for optical connector is produced by mold-forming of plastic resin. If an optical fiber 12 made of, for example, quartz, is inserted into an optical connector ferrule 21 made of plastic resin and the end face thereof is polished (mirror-finished), the polishing quantity of the end of the optical fiber (12) having a high hardness degree is made less than the polishing quantity of the end face of the optical connector ferrule 21 made of plastic resin at a buffing stage in the final finishing process. Thereby, the end of the optical fiber 12 becomes protruded slightly from the end face of the optical connector ferrule 12.
With regards to optical connectors, one end of a fitting pin (not illustrated) is fitted to a fitting pin hole 25 for axial alignment of one optical connector and the other end of the fitting pin is fitted to a fitting pin hole 25 for axial alignment of the other optical connector, wherein one optical connector is placed with the other optical connector with their connection end faces come face to face after the axial alignment is secured between them.
In a case where optical connectors at which the end face of optical fiber 12 remains protruded from the end face of the optical connector ferrule 21 are connected to each other, the end faces of optical fibers 12 are brought into contact with each other whenever connection and disconnection are repeated to cause the end faces of the optical connectors 12 to be damaged, thereby causing the connection loss to be increased.
Therefore, a buffing step in the final finishing process is made difficult.
The present invention can solve the abovementioned themes, and it is therefore an object of the invention to provide a multiple-core optical connector and its manufacturing method, which are made free from any worry about a damage of the end faces of optical fibers.